powerpc/powernv: reboot when requested by firmware

Use orderly_reboot so userspace will to shut itself down via the reboot
path.  This is required for graceful reboot initiated by the BMC, such as
when a user uses ipmitool to issue a 'chassis power cycle' command.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/platforms/powernv/opal-power.c

@@ -29,8 +29,9 @@ static int opal_power_control_event(struct notifier_block *nb,
 
 	switch (type) {
 	case SOFT_REBOOT:
-		/* Fall through. The service processor is responsible for
-		 * bringing the machine back up */
+		pr_info("OPAL: reboot requested\n");
+		orderly_reboot();
+		break;
 	case SOFT_OFF:
 		pr_info("OPAL: poweroff requested\n");
 		orderly_poweroff(true);